511 research outputs found
Star-Free Languages are Church-Rosser Congruential
The class of Church-Rosser congruential languages has been introduced by
McNaughton, Narendran, and Otto in 1988. A language L is Church-Rosser
congruential (belongs to CRCL), if there is a finite, confluent, and
length-reducing semi-Thue system S such that L is a finite union of congruence
classes modulo S. To date, it is still open whether every regular language is
in CRCL. In this paper, we show that every star-free language is in CRCL. In
fact, we prove a stronger statement: For every star-free language L there
exists a finite, confluent, and subword-reducing semi-Thue system S such that
the total number of congruence classes modulo S is finite and such that L is a
union of congruence classes modulo S. The construction turns out to be
effective
Redshift and Shear Calibration: Impact on Cosmic Shear Studies and Survey Design
The cosmological interpretation of weak lensing by large-scale structures
requires knowledge of the redshift distribution of the source galaxies. Current
lensing surveys are often calibrated using external redshift samples which span
a significantly smaller sky area in comparison to the lensing survey, and are
thus subject to sample variance. Some future lensing surveys are expected to be
calibrated in the same way, in particular the fainter galaxy populations where
the entire color coverage, and hence photometric redshift estimate, could be
challenging to obtain. Using N-body simulations, we study the impact of this
sample variance on cosmic shear analysis and show that, to first approximation,
it behaves like a shear calibration error 1+/-epsilon. Using the Hubble Deep
Field as a redshift calibration survey could therefore be a problem for current
lensing surveys. We discuss the impact of the redshift distribution sampling
error and a shear calibration error on the design of future lensing surveys,
and find that a lensing survey of area Theta square degrees and limiting
magnitude m_lim}, has a minimum shear and redshift calibration accuracy
requirements given by epsilon = epsilon_0 10^{beta(m_lim-24.5)} / sqrt(Theta/
200). Above that limit, lensing surveys would not reach their full potential.
Using the galaxy number counts from the Hubble Ultra-Deep Field, we find
(epsilon_0,beta)=(0.015,-0.18) and (epsilon_0,beta)=(0.011,-0.23) for ground
and space based surveys respectively. Lensing surveys with no or limited
redshift information and/or poor shear calibration accuracy will loose their
potential to analyse the cosmic shear signal in the sub-degree angular scales,
and therefore complete photometric redshift coverage should be a top priority
for future lensing surveys.Comment: Accepted version to Astroparticle Physic
Spanish Language Use Across Generations and Depressive Symptoms Among US Latinos
Acculturation markers, such as language use, have been associated with Latino depression. Language use may change between generations; however, few studies have collected intergenerational data to assess how language differences between generations impact depression. Using the Niños Lifestyle and Diabetes Study (2013–2014), we assessed how changes in Spanish language use across two generations of Mexican-origin participants in Sacramento, California, influenced offspring depressive symptoms (N = 603). High depressive symptoms were defined as CESD-10 scores ≥ 10. We used log-binomial and linear-binomial models to calculate prevalence ratios and differences, respectively, for depressive symptoms by language use, adjusting for identified confounders and within-family clustering. Decreased Spanish use and stable-equal English/Spanish use across generations protected against depressive symptoms, compared to stable-high Spanish use. Stable-low Spanish use was not associated with fewer depressive symptoms compared to stable-high Spanish use. Exposure to multiple languages cross-generationally may improve resource access and social networks that protect against depression
Does elite European match-play affect salivary immunoglobulin- a and cortisol in soccer players? The influence of playing status and match outcome
Introduction: The aims of this study were to: a) investigate salivary
immunoglobulin A (s-IgA) and cortisol (s-Cort) responses to nine competitive
fixtures in starting and non- starting soccer players; and b) compare s-IgA and s Cort responses of starters and non-starters considering match outcome.
Methods: Saliva from 19 male outfield players from an elite soccer team (mean ±
SD, age 26 ± 4 years; weight 80.5 ± 8.1 kg; height 1.83 ± 0.07 m; body-fat 10.8% ±
0.7%) was collected. Saliva samples were taken on the day before each match
(MD-1), 60-min before kick-off (MDpre), 30-min post-match (MDpost), and 72-h
post-match (MD+3). There were five wins, one draw and three losses.
Results: The mean s-IgA value was found to be significantly lower at MD+3
compared to MDpre and MDpost. s-Cort was significantly higher at MDpost
compared to MD-1 and MDpre. When compared to MDpre, a statistically
significant decrease in s-Cort was observed at MD+3 compared to MDpost.
Starters displayed higher s-Cort values across the nine matches. There was a
significant group-by-time interaction for s-Cort. There was a significant increase
in s-Cort levels at MDpost compared to MD-1 and from MDpre to MDpost in
starting players. At MDpost, starters had significantly higher s-Cort values. s-IgA
values of starting and non- starting players following successful and unsuccessful
matches did not reveal a significant difference. However, similar analysis of s-Cort
in successful matches showed a significant difference between starters and non starters. s-IgA values at MD-1, MDpre, MDpost and MD+3 in starters and non starters following successful and unsuccessful matches revealed significant
differences at MDpre and MDpost in starters, respectively. Furthermore, s-Cort
values at MD-1, MDpre, MDpost and MD+3 in starters and non-starters in
successful and unsuccessful matches revealed significant differences at MD+3
in starting players.Discussion: The present study suggests that in elite level soccer players, both
starting status and match outcome influence s-IgA and s-Cort responses,
particularly starters. Specifically, s-IgA was lower for starters before and after
the match following successful outcomes. Moreover, higher s-Cort values were
found before the match while lower values occurred after the match for starters in
successful matches.info:eu-repo/semantics/publishedVersio
Ancestral diversity improves discovery and fine-mapping of genetic loci for anthropometric traits-The Hispanic/Latino Anthropometry Consortium
Hispanic/Latinos have been underrepresented in genome-wide association studies (GWAS) for anthropometric traits despite their notable anthropometric variability, ancestry proportions, and high burden of growth stunting and overweight/obesity. To address this knowledge gap, we analyzed densely imputed genetic data in a sample of Hispanic/Latino adults to identify and fine-map genetic variants associated with body mass index (BMI), height, and BMI-adjusted waist-to-hip ratio (WHRadjBMI). We conducted a GWAS of 18 studies/consortia as part of the Hispanic/Latino Anthropometry (HISLA) Consortium (stage 1, n = 59,771) and generalized our findings in 9 additional studies (stage 2, n = 10,538). We conducted a trans-ancestral GWAS with summary statistics from HISLA stage 1 and existing consortia of European and African ancestries. In our HISLA stage 1 + 2 analyses, we discovered one BMI locus, as well as two BMI signals and another height signal each within established anthropometric loci. In our trans-ancestral meta-analysis, we discovered three BMI loci, one height locus, and one WHRadjBMI locus. We also identified 3 secondary signals for BMI, 28 for height, and 2 for WHRadjBMI in established loci. We show that 336 known BMI, 1,177 known height, and 143 known WHRadjBMI (combined) SNPs demonstrated suggestive transferability (nominal significance and effect estimate directional consistency) in Hispanic/Latino adults. Of these, 36 BMI, 124 height, and 11 WHRadjBMI SNPs were significant after trait-specific Bonferroni correction. Trans-ancestral meta-analysis of the three ancestries showed a small-to-moderate impact of uncorrected population stratification on the resulting effect size estimates. Our findings demonstrate that future studies may also benefit from leveraging diverse ancestries and differences in linkage disequilibrium patterns to discover novel loci and additional signals with less residual population stratification
Dissemination as Dialogue: Building Trust and Sharing Research Findings Through Community Engagement
Hubble Space Telescope Weak-lensing Study of the Galaxy Cluster XMMU J2235.3-2557 at z=1.4: A Surprisingly Massive Galaxy Cluster when the Universe is One-third of its Current Age
We present a weak-lensing analysis of the z=1.4 galaxy cluster XMMU
J2235.3-2557, based on deep Advanced Camera for Surveys images. Despite the
observational challenge set by the high redshift of the lens, we detect a
substantial lensing signal at the >~ 8 sigma level. This clear detection is
enabled in part by the high mass of the cluster, which is verified by our both
parametric and non-parametric estimation of the cluster mass. Assuming that the
cluster follows a Navarro-Frenk-White mass profile, we estimate that the
projected mass of the cluster within r=1 Mpc is (8.5+-1.7) x 10^14 solar mass,
where the error bar includes the statistical uncertainty of the shear profile,
the effect of possible interloping background structures, the scatter in
concentration parameter, and the error in our estimation of the mean redshift
of the background galaxies. The high X-ray temperature 8.6_{-1.2}^{+1.3} keV of
the cluster recently measured with Chandra is consistent with this high lensing
mass. When we adopt the 1-sigma lower limit as a mass threshold and use the
cosmological parameters favored by the Wilkinson Microwave Anisotropy Probe
5-year (WMAP5) result, the expected number of similarly massive clusters at z
>~ 1.4 in the 11 square degree survey is N ~ 0.005. Therefore, the discovery of
the cluster within the survey volume is a rare event with a probability < 1%,
and may open new scenarios in our current understanding of cluster formation
within the standard cosmological model.Comment: Accepted to ApJ for publication. 40 pages and 14 figure
Complexity and Information: Measuring Emergence, Self-organization, and Homeostasis at Multiple Scales
Concepts used in the scientific study of complex systems have become so
widespread that their use and abuse has led to ambiguity and confusion in their
meaning. In this paper we use information theory to provide abstract and
concise measures of complexity, emergence, self-organization, and homeostasis.
The purpose is to clarify the meaning of these concepts with the aid of the
proposed formal measures. In a simplified version of the measures (focusing on
the information produced by a system), emergence becomes the opposite of
self-organization, while complexity represents their balance. Homeostasis can
be seen as a measure of the stability of the system. We use computational
experiments on random Boolean networks and elementary cellular automata to
illustrate our measures at multiple scales.Comment: 42 pages, 11 figures, 2 table
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